What is the difference between kn95 and N95 FFP2 KF94 etc.?

The N series of masks are American standards, the kn series are Chinese standards, the FFP series are European standards, and the KF series are Korean standards

The number refers to the protection ability, the greater the number, the higher the degree of protection.

95 means that the effective rate of filtration of such particles reaches 95%.

Series 90 is not as high as 95, but it can also resist more than 90% of particles.

In FFP series, 2 basically corresponds to 95, and 3 has a higher efficiency of filtering, up to 99%.

It is easier to understand the filtering ability by the following relationship:

FFP3 > FFP2 = N95 = KN95 = KF94 > KN90

What is the difference between valved mask and no valve?

The protective performance of valve mask is the same as no valve mask

Function of breathing valve: in hot and humid working environment with poor ventilation , breathing valve can help you feel more comfortable.

The function principle of the breathing valve is that.

Positive pressure is generated by exhaling, the valve plate is blown open, gas in the body is discharged rapidly, so the sense of stuffy heat is relieved.

When inhaling, the negative pressure will automatically close the valve to avoid inhaling pollutants from the external environment